Effect of poly(tert-butyl methacrylate) stereoregularity on polymer film interactions with peptides, proteins, and bacteria

The impact of polymer stereoregularity on its interactions with peptides, proteins and bacteria strains was studied for three stereoregular forms of poly(tert-butyl methacrylate) (PtBMA): isotactic (iso), atactic (at) and syndiotactic (syn) PtBMA. Principal component analysis of the time-of-flight secondary ion mass spectrometry data recorded for thin polymer films indicated a different orientation of ester groups, which in the case of iso-PtBMA are exposed away from the surface whereas for at-PtBMA and syn-PtBMA these are located deeper within the film. This arrangement of chemical groups modified the interactions of iso-PtBMA with biomolecules when compared to at-PtBMA and syn-PtBMA. For peptides, the affected interactions were explained by the preferential hydrogen bonding and electrostatic interaction between the exposed polar ester groups of iso-PtBMA and positively charged peptides. In turn, for protein adsorption no impact on the amount of adsorbed proteins was observed. However, the polymer stereoregularity influenced the orientation of immunoglobulin G and induced conformational changes in bovine serum albumin structure. Moreover, the impact of polymer stereoregularity occurred equally for their interactions with Gram-positive bacteria (S. aureus), which absorbed preferentially onto iso-PtBMA films as compared to two other stereoregularities.

[Laryngeal mask of gastroesophageal reflux disease]

Gastroesophageal reflux disease has become a serious problem not only for general practitioners but for other specialists as well. It is caused by the fact that its clinical picture and symptomatology are very rich. Beside characteristic symptoms such as: heartburn, eructation, gastric contents reflux, epigastric burning or dysphagia, there may appear extroesophageal symptoms (frequently as single or leading ones). It is generally though that the above symptoms result from the direct effect of gastric contents on throat and larynx and/or through vagus nerve. Direct effect of hydrochloric acid and other gastric juice components on larynx may be the cause of subglottic laryngostenosis, neoplastic transformation and development of squamous cell carcinoma. This, it may be concluded that gastroesophageal reflux disease should be in the sphere of interest of laryngologists as well as gastroenterologists. Cooperation of these specialists is particularly useful as it quickens the choice of proper diagnostic procedure and an introduction of an appropriate therapeutic treatment.

[Vitamin C in treatment of certain cardiovascular diseases]

The human organism is incapable of producing vitamin C by biosynthesis. We are therefore totally dependent on the presence of this vitamin in our diet. Vitamin C is capable of essentially influencing the course of many metabolic processes, and it is therefore used in the treatment and prophylaxis of many diseases, including those that are a consequence of the activity of the so-called reactive forms of oxygen. The presence of vitamin C in the anti-oxidant protective system is believed to be very important, since it can react with the free radicals of oxygen and other oxidants, and "sweep" them away. Therefore, attention is more and more frequently focused on the possibility of using vitamin C in the treatment of those circulatory diseases that are believed to be associated with the action of free radicals. Routine administration of vitamin C should be therefore recommended in the treatment of patients with coronary arterial disease, treatment of patients after cardiac infarction or cerebral stroke, or in the treatment of arterial hypertension.

[Effect of prokinetic drugs inhibiting dopaminergic system on gallbladder motility in subjects with duodenal ulcer]

The purpose of this study was to determine the effect prokinetic drugs inhibiting dopaminergic receptors on gallbladder volume in normal conditions. The study comprised 90 males, aged 20-26 years with duodenal ulcer disease in remission alloted into 3 groups, 30 subject each. The gallbladder volume was determined in group I after placebo or 10 and 20 mg or metoclopramide administration; in group II: placebo or 10 and 20 mg of domperidone and in group III after placebo or 50 and 100 mg of sulphiride administration. Gallbladder motility was assessed ultrasonographically from 15 minutes to 2 hours since placebo or drug administration. The effect of the studied prokinetic drugs in fasting on gallbladder motility was differentiated after metoclopramide no significant changes in gallbladder volume were observed; after domperidone in the dose of 20 mg a slight decrease of gallbladder volume was found, whereas after sulphiryde statistically significant decrease was detected.

[Vitamin C in medicine: "normal concentration" in serum]

Vitamin C functions in a human organism have been discussed. Connection with many diseases and its systemic deficiency has been emphasized. A review of current application of this vitamin in medicine has been made. Problems accompanying the use of reference sources of vitamin C "normal concentrations" in blood plasma have been characterised. 10 ranges of concentrations given by medical handbooks and textbooks have been compared in detail with 15 parallel ranges taken from scientific papers, paying attention to their significant discrepancies. Basing on source values, performing basic statistical calculations, a reliable mean range of vitamin C "normal concentrations" in blood plasma has been obtained: 36.1-79.4 mumol/l.

Effect of cisapride and cimetidine on 24-hour intraesophageal pH monitoring in patients with gastroesophageal reflux disease

In 16 patients with symptomatic gastroesophageal reflux disease (GERD) 24-h intraesophageal pH monitoring (Medilog 1010, Oxford) was carried out after placebo, cisapride (4 x 5 mg) and cimetidine (3 x 200 mg plus 400 mg at bedtime). The per cent time at which intraesophageal pH < 4.0 (refluxive time) was analysed. Cisapride shortened daytime and postprandial refluxive time from 16.1 +/- 14.5% and 12.6 +/- 9.2% to 5.1 +/- 4.4% and 7.5 +/- 6.5%, respectively (p < 0.01, p < 0.05). Whereas, cimetidine shortened particularly night refluxive time from 24.7 +/- 14.1% to 8.8 +/- 6.9% (p < 0.01) and total time from 20.4 +/- 12.8% to 12.0 +/- 6.4% (p < 0.05).

[Effect of cimetidine on the heart conduction system]

An effect of cimetidine on ECG records has been investigated in a group of 40 patients with gastric or duodenal ulcers and coexisting circulatory disorders. For this purpose ECG has been recorded with Holter's technique (Medilog 2000) together with ECG-recording using high amplifying technique. An intravenous injection of 200 mg of cimetidine produced in some of patients inhibition of the sinus rhythm atrio-ventricular conduction disturbances as well as changes in the end phase of ECG ventricular image. The authors suggest, that intravenous administration of cimetidine to patients with cardiac diseases should be monitored with ECG recording.

[Effectiveness of sucralfate in the treatment of gastric ulcer in women during menopause--comparison with cimetidine]

The reported study was done in 60 women aged 44 to 60 years during menopause. In group I (n = 30) sucralfate was used (Venter, Krka) in doses of 1.0 g daily. The rate of symptom disappearance and ulcer healing and the frequency of recurrences were assessed. It was observed that the rate of ulcer healing after sucralfat was higher and recurrences were leas frequent.